KR20000071564A - Method and apparatus for controlling presentation of digital video data - Google Patents

Abstract

The present invention relates to a method and apparatus for replaying a portion of a predetermined program immediately preceding the present presentation time. The on-screen display is automatically activated during replay of a portion of a predetermined program to allow viewers to better understand conversations that may be missed or difficult to hear due to ambient noise. In particular, the present invention provides a transducer for retrieving digital video data units and control data units from a video data source and for providing digitally encoded data, and a transducer for decoding a display from the digitally encoded data. A decoder coupled to, and for representing the program based on the sequence of video data units in response to the first user input and for replaying a portion of the predetermined program preceding the current presentation time in response to the second user input. And a controller, wherein the controller provides an on-screen display while iteratively replaying a portion of a predetermined program preceding the current presentation time. The present invention is particularly suitable for processing data encoded according to the DVD standard.

Description

TECHNICAL AND APPARATUS FOR CONTROLLING PRESENTATION OF DIGITAL VIDEO DATA

This application claims the benefit of U.S. 60 / 131,815 provisionally filed in the United States on April 29, 1999.

The present invention relates to a method and apparatus for controlling the presentation of a video program based on a digital data stream, and more particularly to a user to easily replay a predetermined program portion before a current presentation point, and A method and apparatus are provided for bringing up an on-screen display associated with a program during a repeat play period.

The video signal processing system uses the storage media having video and audio information digitally compressed and stored on the storage media, and provides a user with an enormous amount of options for controlling the presentation of a program, such as a video title stored on such storage media. Can be provided to Such a rapidly gaining system includes a video disc player suitable for processing information stored in accordance with the digital video disc (DVD) standard. Information on a DVD-type disc is recorded in separate data packets according to video and audio compression standards, where designated packets carry data associated with various data streams, such as selectable video angles, audio tracks, sub-picture streams, and the like. . A video disc player that reads a disc in DVD form may be controlled to display or represent a particular data packet and skip other data packets. By using this feature, the DVD system allows disc authors to provide various variations of video titles as well as various on-screen displays to satisfy viewers' preferences.

Often viewers want to repeat a portion of a predetermined program during a particular viewing. This can happen when a viewer wants to repeat a short portion of a program that he or she could miss during normal playback, or especially enjoyed. Also, if a particular screen contains loud music and sound effects that make the conversation inaudible, the viewer may want to play only that screen in order to hear again the part of the conversation they missed.

Viewers generally have many options for repeating a portion of a program during normal playback. The viewer can jump backwards to the beginning of a previously defined program block, such as a chapter on a DVD. The viewer can play the program at the fastest speed in either the forward or reverse mode until the desired point of the program is found, and then resume playback at the normal speed. The viewer can set the repeat mode to repeat playback of the program block defined by the viewer by setting the A-B point on the predefined program block or the disc.

However, this method generally requires several key presses and is inconvenient when the viewer wants to repeatedly play only a short section of the program immediately preceding the current presentation point. If the viewer wants to better understand the missed conversation, the viewer manually turns on the subtitle, searches for the desired jump point, and switches off the subtitle after repeat playback is complete. However, this adds more keypress operations to the sequence, and the viewer has to manually adjust switching the subtitle on and off according to the search and presentation, which can be difficult and cumbersome. Thus, various key press operations and inconveniences tend to disrupt the flow of the program and reduce the viewer's satisfaction with the program.

Therefore, what is needed is a method and apparatus for enabling a viewer to easily repeat a portion of a predetermined program immediately preceding the current presentation point.

In addition, what is needed is a way for the viewer to view the selected on-screen display (OSD) in relation to the repeat play section so that the viewer can easily repeat the portion of the predetermined program immediately preceding the current presentation point. And a method and apparatus for making it.

What is also needed is a method and apparatus for allowing a viewer to easily repeat a portion of a predetermined program immediately preceding the current presentation point, wherein the program data is formatted according to the DVD standard.

The present invention allows a viewer to easily repeat a portion of a predetermined program preceding a current presentation point in response to a user input. The present invention also provides an on-screen display such as a subtitle during the repeat playback section according to the preferences selected by the viewer.

In an exemplary embodiment suitable for use with data formatted according to the DVD standard, the present invention provides a method for rendering a program based on a selected sequence of representation data units; Detecting a repeat play request input by the user; Determining a repeat play start time in response to a repeat play request input by the user; Detecting the expression data unit related to the repetition reproduction start time and restarting the expression of the program from the repetition reproduction start time; And providing an on-screen display relating to the program when resuming expression of the program from the repeat playback start time. Advantageously, the on screen display comprises a subtitle.

Furthermore, the present invention is a video processing apparatus, wherein the video processing apparatus is a transducer for retrieving the program data including a digital representation data unit and a control data unit from a program data source, each digital representation data. The unit is associated with each control data unit, each representation data unit corresponds to a predetermined program segment, and the transducer retrieves the representation sequence and the control data unit in response to data input by the user and digitally. A transducer for providing encoded data; A decoder coupled to a transducer to decode a display from the digitally encoded data; And a controller coupled to the decoder and the transducer, the controller for representing a program based on a sequence of representation data units in response to a first viewer input, repetitively playing back a portion of a predetermined program immediately preceding the current representation point. And a controller that provides an on-screen display associated with the program while repeatedly playing back a portion of the predetermined program immediately preceding the current presentation point in response to the second user input.

The invention will be described with reference to the accompanying drawings.

1 is a block diagram of a digital video disc player suitable for implementing the repeat playback feature of the present invention.

Fig. 2 is a diagram showing a data structure suitable for implementing the repeat reproduction characteristic of the present invention in accordance with the DVD format.

Fig. 3 is a block diagram of a representation structure suitable for implementing the repeat reproduction characteristic of the present invention in accordance with the DVD format.

4 is a flowchart illustrating steps for implementing repetitive playback of the present invention.

<Explanation of symbols for the main parts of the drawings>

24: Disk Flare 26: Motor and Pickup Assembly

27: preamplifier 28: DVD data processing unit

29 Servo Processor 30 Digital Audio / Video Decoder

40: microcontroller 41: user control device

Although the exemplary embodiment has been described with reference to a digital video apparatus suitable for reading compressed program data including video, audio and control data from a disc and processing the program data in accordance with the DVD specification, the present invention is directed to digital May be used in any video processing apparatus capable of processing video and audio information, and program-related information including video and audio information may be used to selectively present portions of the video and audio information, and each It should be understood that the program data unit relates to the presentation time data.

1 is a block diagram illustrating the basic elements of an exemplary digital video disc player 24 suitable for controlling the presentation of digital program data in accordance with the present invention. The construction and operation of such elements are generally known and will not be discussed in detail herein. The disc player 24 includes a motor and pickup assembly 26 for rotating the disc under the control of a servo processor 29 to read the information stored on the disc. The preamplifier 27 and the DVD data processing unit 28 convert electric pulses from the motor and pickup assembly 26 into digital data which can also be processed by the digital audio / video decoder unit 30. The DVD data processing unit 28 generally provides demodulation, error correction and descrambling of the raw data read from the disc to provide digitally encoded data in a form suitable for the decoder unit 30. It performs the same function.

Decoder unit 30 receives digitally encoded data, processes the data, and provides appropriate video and audio signals to a display unit, such as a television set. Decoder unit 30 demultiplexes the data from data processing unit 28 into a number of separate data streams, such as, for example, video streams, audio streams, and sub-picture streams, and decodes the data streams to respective data decoders of the stream. Providing a datastream de-multiplexer 32. The video decoder 31 receives the video stream, decodes the signal according to the MPEG-2 standard, and provides the video signal to the mixer 33. The sub-picture decoder 34 receives the sub-picture stream and provides data to the OSD control unit 35 which provides an OSD (on screen display) video signal to the mixer 33. The combined video signal from mixer 33 is provided to NTSC / PAL encoder 42, which provides a video signal to the video display device that conforms to the appropriate video signal standard. Audio decoder 36 receives the audio stream from datastream demultiplexer 32 and provides the appropriate audio signal to the audio system.

The microcontroller 40 controls the operation of the disc player 24. The microcontroller 40 is connected to a user control device 41 which may include an IR remote control device such as a front panel button or the like. The microcontroller 40 converts data from the user control device 41 to control the operation of the various elements of the disc player 24 described above. Various parameters and data for representing the data stream may be stored in the memory 38. The microcontroller 40 may be implemented in many forms including but not limited to a dedicated integrated circuit, that is, part of a decoder / controller unit. The microcontroller 40 may be comprised of one of a number of suitable controller units, including but not limited to STI5500 manufactured by SGS Thomson.

Fig. 2 shows the structure of program data and control data stored on a disc according to the DVD standard and suitable for representation by the disc player 24. Figs. The data structure is hierarchical, and each data block is divided into component data blocks, which are further divided into smaller component data blocks. For example, each video title set corresponding to a designated program unit, such as an episode of a movie or television show, is composed of a set of video objects and includes a plurality of video objects.

Each video object is composed of a plurality of cells, each cell being considered a representation data unit having a plurality of program data types such as video, audio, subpicture, etc. and corresponding to program segments. Each cell is in turn composed of a number of video object units (VOBUs). Each VOBU consists of a navigation pack (NAV_PACK) and a number of packs, which are subdivided into a number of packs. The VOBU generally corresponds to an MPEG-2 Group of Picture (GOP), and the NAV_PACK contains control data related to the VOBU. Each NAV_PACK holds information such as the sector address of the VOBUs for both the current VOBU (both the preceding sector and the later sector in the temporal representation order) and the amount of time elapsed in the cell representation corresponding to the current VOBU.

Data stored in accordance with the DVD standard is also logically organized as an expression structure to provide flexibility in the manner in which the data can be represented. 3 shows a representation structure suitable for using the disc player 24 according to the DVD standard. This representation structure is overlaid in the data structure of FIG. At the reference level, the presentation sequence is defined via programs PGs 96, each program PGs comprising a linked list of pointers to cells. Multiple PGs 96 may be combined to form program chain information (PGCI) 94, and the multiple PGCIs may be combined in sequence to form program chain (PGC) 92.

During the presentation, the disc player 24 retrieves the appropriate cell from the disc according to the PGC, demultiplexes the data in the cell, and prepares the data for presentation. In this regard, NAV_PACKs are resolved and the address of the NAV_PACK can be stored for later use. Since each NAV_PACK is related to an elapsed time value, the NAV_PACK can be used to resume the presentation at a particular elapsed time after stopping, or can be used for the time-editing feature. In the present invention, the microcontroller 40 converts the relative elapsed time data of each NAV_PACK into an absolute elapsed time value and stores the NAV_PACK address in the memory 38 or any other suitable memory device. Therefore, when the user requests repeat play, the specific NAV_PACK address related to the specific elapsed time value can be easily and quickly accessed.

According to the present invention, when the user requests repeat playback, the microcontroller 40 obtains the current presentation time, determines the desired repeat playback start time, and based on the elapsed time data stored in the memory 38, The desired NAV_PACK address associated with the repeat playback start time is determined, and the expression is restarted from the desired repeat playback start time based on the desired NAV_PACK. The address of the NAV_PACK as stored is used as the point to resume playback. The address can be regarded as a starting sector to begin demultiplexing content and to start presenting the content. The ending sector is also the last sector in the cell. Thus, the representation starts again from the previous point, and the delimiter of the representation is the end address of the cell containing the associated NAV_PACK address and VOBU.

Depending on the DVD format, NAV_PACK is analyzed almost every .4-.6 seconds for the presentation material. This means that the effective sampling rate is sufficient to jump backwards over the one second presentation time boundary. Using the stored NAV_PACK address, disc player 24 can jump backward to a predetermined time prior to the current presentation time. The NAV_PACK address is indexed by the elapsed time information of the address to make it easier to retrieve the desired NAV_PACK when the user wants to jump backwards by a predetermined time.

Advantageously, the NAV_PACK address may be stored in circular memory to facilitate the selection of the desired NAV_PACK and to reduce memory requirements. The circular memory may be formed as part of the microcontroller 40 or the memory 38, for example. In addition, the NAV_PACK address may be stored so that it can be retrieved in a predetermined interval, thereby allowing the user to jump backward by a multiple of the predetermined time interval. For example, by pressing the repeat button once, the disc player 24 may be remedied for repeating the previous five seconds, while pressing the repeat button twice causes the disc player 24 to repeat. Repeat the previous 10 seconds and follow the above relationship. Optionally, a replay section associated with pressing each button may be arranged for the user to select. The selection of the repeat playback request and the repeat playback section may be input by the user using any one of the known user interface methods, for example by using a remote control device and / or an on screen display.

Since storing all NAV_PACK addresses for the entire title is quite memory intensive, the NAV_PACK addresses for only a predetermined amount of time so far are stored in memory 38. If the user wants to jump backward for a time period exceeding the stored time period, a time-search algorithm can be used to determine the desired presentation time and the NAV_PACK address associated with the desired presentation time. This algorithm may use a time map (TIME MAP) contained on the disc for any title of type One_Sequential_PGC. The time map table contains sector addresses for NAV_PACKs starting at each time interval. The time granularity of this interval may vary (and may be greater than the resolution of 1 second). Thus, the algorithm can jump to NAV_PACK starting at the closest time to be searched, and then search forward in the stream until NAV_PACK is found with the presentation material starting at the exact moment to be searched.

Once the desired representation time is determined and the NAV_PACK associated with the desired representation time is accessed, the program representation begins again. As mentioned above, the viewer may want to repeat a portion of the program to hear the missed conversation again. In this regard, when the expression resumes at the desired expression time, the microcontroller 40 automatically turns on the subtitle according to the user set language preference. Optionally, the selected subtitle may correspond to the last used subtitle language or default language, or the subtitles may all be turned off according to user preference. When the expression reaches the expression time corresponding to the time at which the repeat playback request is received, the microcontroller 40 automatically turns off the subtitle. By looking at the subtitle display, the viewer can easily understand any conversation that may be difficult to understand or hear due to ambient noise. In this way, the disc player 24 repeatedly plays back a portion of a predetermined program in response to only one user input, and provides a subtitle during the repeat playback section, thereby alleviating the inconvenience of the above-mentioned user. Let's do it.

Figure 4 shows a flow chart for implementing the instantaneous repeat playback characteristics in accordance with the present invention. Under normal presentation conditions, the disc player 24 retrieves the program data from the disc as indicated in step 102 and expresses the selected title according to a predetermined sequence. As mentioned above, the disc player 24 analyzes for every NAV_PACK encountered in the stream during presentation, converts the relative elapsed time value of the NAV_PACK into an absolute elapsed time value, and overwrites the NAV_PACK address with the oldest value. The NAV_PACK address is stored in a circular buffer.

In step 104, the disc player 24 determines whether a user input for requesting instant repeat playback has been received. If not received, the disc player 24 continues the normal representation as indicated in step 102. If a momentary repeat playback request has been received, then in step 106 the disc player 24 calculates the current elapsed presentation time, stores the current elapsed presentation time, and determines the desired presentation time in step 108. To subtract the desired time from the current elapsed representation time. As determined in step 110, if the NAV_PACK address for the desired presentation time has been stored in the memory 38, the disc player 24 accesses the NAV_PACK and resumes the presentation starting from the NAV_PACK. If the desired NAV_PACK address is not stored, the time-search algorithm is used to determine the desired presentation time and NAV_PACK address as indicated in step 112, indicating that the user wants to jump backwards over a relatively large time period. do.

Once the desired NAV_PACK address is found, the presentation resumes based on the desired NAV_PACK as indicated in step 114 and the subtitle is automatically turned on as indicated in step 116. The subtitle may be turned on according to a user set preference or may be turned on according to the last subtitle used. The representation for the subtitle continues when the instant repeat playback request is detected in step 104, until the representation reaches the original representation time. At that time, the subtitle is turned off as indicated in step 118 and the representation continues in the normal manner as indicated in step 102.

Although the present invention has been described in terms of exemplary embodiments, it will be apparent to those skilled in the art that changes and modifications will be made to disclose the embodiments without departing from the spirit of the invention. As an example, although embodiments of the present invention display subtitles during repeat playback, an on-screen display may be produced, included in a disc or data source, and include other program related information that may be selected by the viewer for display. It is clear that it can be done. Such displays include, but are not limited to, textual information about the manager's description, cast member description, instructional commentary, and the like. In addition, any of the conventionally known methods suitable for storing and accessing the data address in the presentation time data related to the data address may be used. Also, memory 38 may be formed as part of microcontroller 40 rather than each device.

The instantaneous repetitive playback characteristics of the present invention are one example of a number of methods known in the art for controlling various elements of the above-described disc player 24 using software embedded in the microcontroller 40. It is recognized herein that it can be implemented using a method, or a combination of the above methods. In addition, the instantaneous repetitive reproduction feature of the present invention may be implemented with any signal processing system, which provides a means for storing the current elapsed representation time and the address of the previously expressed program portion. It can be configured to selectively display a program. Therefore, it will be understood that the present invention is intended to cover all modifications as included within the obvious scope and spirit of the present invention.

Claims (20)

A system suitable for retrieving and presenting a sequence of digital representation data units, the method for controlling the representation of the representation data unit, comprising a plurality of digital representation data units and a control data unit, each representation data unit being a dictionary. Retrieving program data corresponding to the program segment determined therein and having information related thereto, and expressing the retrieved data unit according to the selected sequence in response to a play request input by the user ( A method for controlling a representation of said representation data unit, comprising presenting (102), Detecting a replay request input by the user (104); In response to the repetitive playback request input by the user, determining 108 a repeat playback start time and resuming the representation of the representation data unit from the repeat playback start time 114; and Providing (116) an on-screen display relating to a program upon resuming the representation of the representation data unit from the repeat playback start time. The method of claim 1, wherein the on-screen display comprises a subtitle. The method as claimed in claim 1, wherein the providing step comprises providing (116, 118) an on-screen display related to the program during the presentation period from the start time of the repeat play to the presentation time corresponding to the time when the repeat play request input by the user is detected. And a representation of the representation data unit. 2. The method of claim 1, wherein the presenting step comprises analyzing 106 the control data unit associated with the representation data unit and storing address data associated with the control data unit in a circular buffer. And a representation of the representation data unit. 5. The control data unit of claim 4, wherein the control data unit comprises NAV_PACKs according to the DVD standard, wherein the presenting step comprises parsing 106 of the NAV_PACKs and using relative elapsed time of each NAV_PACK as an absolute elapsed time value. Converting, and storing each NAV_PACK address in a memory device. 6. The method of claim 5, wherein the resuming comprises: retrieving a desired NAV_PACK address from the memory (110), retrieving a representation data unit associated with the desired NAV_PACK, and a representation of a program from the retrieved representation data unit. Restarting (114) the method of controlling the representation of the representation data unit. 7. The method of claim 6, wherein the determining step comprises the steps of determining the present expression time (110, 114), subtracting the desired time from the present expression time to determine the repeat play start time, and the repeat play. Retrieving the control data unit related to a start time. 7. The method of claim 6, wherein the determining step comprises using (112) a time search algorithm to determine the repeat playback start time. As a digital video system, As a transducer for retrieving the program data comprising a digital representation data unit (VOBU) and a control data unit (NAV_PACK) from a program data source, each digital representation data unit is associated with a respective control data unit and Each representation data unit corresponds to a predetermined program segment (cell), and the transducer retrieves the representation sequence and the control data unit in response to data input by the user and retrieves the digitally encoded data. Providing transducer 26, Decoders 28 and 30 coupled to the transducer for decoding a display from the digitally encoded data, and A digital video system, comprising a controller coupled to the decoders 28 and 30 and the transducers 26, for representing a sequence of the representation data unit in response to a first viewer input. While the controller repeats playback of the portion of the predetermined program immediately preceding the current representation point (114), and replays the portion of the predetermined program immediately preceding the current representation point in response to the second user input. A digital video system, characterized by providing (116, 118) an on screen display associated with a program. 10. The digital video system of claim 9, wherein the on screen display comprises a subtitle. 10. The digital video system according to claim 9, wherein the controller analyzes (106) the representation data unit and the control data unit during representation and stores address data related to the control data unit in a circular buffer. 10. The apparatus of claim 9, wherein the control data unit comprises NAV_PACKs in accordance with a DVD specification, the controller analyzes the NAV_PACKs during the presentation (106), and converts the relative elapsed time of each NAV_PACK into an absolute elapsed time value. And storing each NAV_PACK address in a memory device. 13. The apparatus of claim 12, wherein the controller retrieves a desired NAV_PACK address from the memory device (110), controls the transducer to retrieve the representation data unit associated with the desired NAV_PACK, and controls the second viewer input. And resume (114) the representation based on the retrieved representation data unit data in response. 15. The apparatus of claim 13, wherein the controller determines, in response to the second viewer input, the desired presentation time by determining a current presentation time (108) and subtracting a predetermined time from the current presentation time. Retrieving a representation data unit associated with said desired NAV_PACK. Retrieving and presenting the sequence of video data units in response to a first viewer input (102), and repeating a predetermined portion of the sequence of video data units immediately preceding a present presentation time in response to a second viewer input. 10. A method of representing a sequence of digitally encoded video data units and control data units, comprising the step of playing 114. Providing (116, 118) an on-screen display relating to the program during the iterative reproduction of the predetermined portion of the video data unit sequence in response to the second viewer input. To represent a sequence of video data units and control data units. 16. The method of claim 15, wherein said providing step 116 comprises providing a subtitle according to a preference selected by the viewer. Way. 16. The method of claim 15, wherein said retrieving and presenting comprises retrieving 106 said control data unit associated with said video data unit, and storing address data associated with each said control data unit in a circular buffer. And a sequence of digitally encoded video data units and control data units. 16. The sequence of digitally encoded video data units and control data units according to claim 15, characterized in that the step of repeating playback comprises repeatedly playing back a plurality of predetermined intervals for the sequence of video data units. How to express it. 16. The method of claim 15, wherein the repeat playback step comprises the steps of: determining a repeat playback start time by determining a current representation time and subtracting a predetermined time period from the current representation time, and at the repeat playback start time. Retrieving the associated control data unit. A method of representing a sequence of digitally encoded video data units and control data units. 16. The sequence of digitally encoded video data units and control data units according to claim 15, characterized in that the step of repeating playback comprises the step 112 of determining a repeat playback start time using a time search algorithm. How to express it.